| 摘要 |
PROBLEM TO BE SOLVED: To provide the most advantageous thickness of a solder cell for the photoelectric conversion efficiency and reduce the carrier recombination loss. SOLUTION: An upper cell 12 composed of an n<+> layer, p-layer and p<+> layer and a lower cell 14 having an n<+> layer and p<+> layer arranged along the back side at the lower part of the p-layer are laminated to constitute the solder cell 10. The band gap of the upper cell 12 is greater than that of the lower cell 14, an upper electrode 18 is formed on the n<+> layer of the upper cell 12, a negative electrode 26 and positive electrode 28 are independently formed on the n<+> layer and p<+> layer of the lower cell 14, respectively, to form a pair of electrodes of the lower cell 14, and the positive electrode 28 is combinedly used for the other electrode of the upper cell 12. Thus it is possible to take up minority carriers generated in the upper and lower cells 12, 14 from the electrodes of the cells. |
